2015-07-28 10:34:24

by Chao Yu

[permalink] [raw]
Subject: [PATCH v2] f2fs: shrink free_nids entries

This patch introduces __count_free_nids/try_to_free_nids and registers
them in slab shrinker for shrinking under memory pressure.

Signed-off-by: Chao Yu <[email protected]>
---
v2:
* fix wrong bug_on in try_to_free_nids.

fs/f2fs/f2fs.h | 1 +
fs/f2fs/node.c | 28 ++++++++++++++++++++++++++++
fs/f2fs/segment.c | 3 +++
fs/f2fs/shrinker.c | 14 ++++++++++++++
4 files changed, 46 insertions(+)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 58b05b5..a8e07cd 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1682,6 +1682,7 @@ int sync_node_pages(struct f2fs_sb_info *, nid_t, struct writeback_control *);
bool alloc_nid(struct f2fs_sb_info *, nid_t *);
void alloc_nid_done(struct f2fs_sb_info *, nid_t);
void alloc_nid_failed(struct f2fs_sb_info *, nid_t);
+int try_to_free_nids(struct f2fs_sb_info *, int);
void recover_inline_xattr(struct inode *, struct page *);
void recover_xattr_data(struct inode *, struct page *, block_t);
int recover_inode_page(struct f2fs_sb_info *, struct page *);
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index ac91107..6e10c2a 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1635,6 +1635,34 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
kmem_cache_free(free_nid_slab, i);
}

+int try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+ struct f2fs_nm_info *nm_i = NM_I(sbi);
+ struct free_nid *i, *next;
+ int nr = nr_shrink;
+
+ if (!mutex_trylock(&nm_i->build_lock))
+ return 0;
+
+ spin_lock(&nm_i->free_nid_list_lock);
+ list_for_each_entry_safe(i, next, &nm_i->free_nid_list, list) {
+ if (nr_shrink <= 0 || nm_i->fcnt <= NAT_ENTRY_PER_BLOCK)
+ break;
+ if (i->state == NID_ALLOC)
+ continue;
+ __del_from_free_nid_list(nm_i, i);
+ nm_i->fcnt--;
+ spin_unlock(&nm_i->free_nid_list_lock);
+ kmem_cache_free(free_nid_slab, i);
+ nr_shrink--;
+ spin_lock(&nm_i->free_nid_list_lock);
+ }
+ spin_unlock(&nm_i->free_nid_list_lock);
+ mutex_unlock(&nm_i->build_lock);
+
+ return nr - nr_shrink;
+}
+
void recover_inline_xattr(struct inode *inode, struct page *page)
{
void *src_addr, *dst_addr;
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 509a2c4..4712dbc 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -317,6 +317,9 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
if (!available_free_memory(sbi, NAT_ENTRIES))
try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK);

+ if (!available_free_memory(sbi, FREE_NIDS))
+ try_to_free_nids(sbi, NAT_ENTRY_PER_BLOCK * FREE_NID_PAGES);
+
/* checkpoint is the only way to shrink partial cached entries */
if (!available_free_memory(sbi, NAT_ENTRIES) ||
excess_prefree_segs(sbi) ||
diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
index 9aa4235..da0d8e0 100644
--- a/fs/f2fs/shrinker.c
+++ b/fs/f2fs/shrinker.c
@@ -23,6 +23,13 @@ static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
return NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt;
}

+static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)
+{
+ if (NM_I(sbi)->fcnt > NAT_ENTRY_PER_BLOCK)
+ return NM_I(sbi)->fcnt - NAT_ENTRY_PER_BLOCK;
+ return 0;
+}
+
static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi)
{
return sbi->total_ext_tree + atomic_read(&sbi->total_ext_node);
@@ -53,6 +60,9 @@ unsigned long f2fs_shrink_count(struct shrinker *shrink,
/* shrink clean nat cache entries */
count += __count_nat_entries(sbi);

+ /* count free nids cache entries */
+ count += __count_free_nids(sbi);
+
spin_lock(&f2fs_list_lock);
p = p->next;
mutex_unlock(&sbi->umount_mutex);
@@ -97,6 +107,10 @@ unsigned long f2fs_shrink_scan(struct shrinker *shrink,
if (freed < nr)
freed += try_to_free_nats(sbi, nr - freed);

+ /* shrink free nids cache entries */
+ if (freed < nr)
+ freed += try_to_free_nids(sbi, nr - freed);
+
spin_lock(&f2fs_list_lock);
p = p->next;
list_move_tail(&sbi->s_list, &f2fs_list);
--
2.4.2


2015-08-05 09:28:13

by Chao Yu

[permalink] [raw]
Subject: RE: [f2fs-dev] [PATCH v2] f2fs: shrink free_nids entries

Hi Jaegeuk,

Any comments?

> -----Original Message-----
> From: Chao Yu [mailto:[email protected]]
> Sent: Tuesday, July 28, 2015 6:34 PM
> To: Jaegeuk Kim
> Cc: [email protected]; [email protected]
> Subject: [f2fs-dev] [PATCH v2] f2fs: shrink free_nids entries
>
> This patch introduces __count_free_nids/try_to_free_nids and registers
> them in slab shrinker for shrinking under memory pressure.
>
> Signed-off-by: Chao Yu <[email protected]>
> ---
> v2:
> * fix wrong bug_on in try_to_free_nids.
>
> fs/f2fs/f2fs.h | 1 +
> fs/f2fs/node.c | 28 ++++++++++++++++++++++++++++
> fs/f2fs/segment.c | 3 +++
> fs/f2fs/shrinker.c | 14 ++++++++++++++
> 4 files changed, 46 insertions(+)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 58b05b5..a8e07cd 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -1682,6 +1682,7 @@ int sync_node_pages(struct f2fs_sb_info *, nid_t, struct writeback_control
> *);
> bool alloc_nid(struct f2fs_sb_info *, nid_t *);
> void alloc_nid_done(struct f2fs_sb_info *, nid_t);
> void alloc_nid_failed(struct f2fs_sb_info *, nid_t);
> +int try_to_free_nids(struct f2fs_sb_info *, int);
> void recover_inline_xattr(struct inode *, struct page *);
> void recover_xattr_data(struct inode *, struct page *, block_t);
> int recover_inode_page(struct f2fs_sb_info *, struct page *);
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index ac91107..6e10c2a 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -1635,6 +1635,34 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
> kmem_cache_free(free_nid_slab, i);
> }
>
> +int try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink)
> +{
> + struct f2fs_nm_info *nm_i = NM_I(sbi);
> + struct free_nid *i, *next;
> + int nr = nr_shrink;
> +
> + if (!mutex_trylock(&nm_i->build_lock))
> + return 0;
> +
> + spin_lock(&nm_i->free_nid_list_lock);
> + list_for_each_entry_safe(i, next, &nm_i->free_nid_list, list) {
> + if (nr_shrink <= 0 || nm_i->fcnt <= NAT_ENTRY_PER_BLOCK)
> + break;
> + if (i->state == NID_ALLOC)
> + continue;
> + __del_from_free_nid_list(nm_i, i);
> + nm_i->fcnt--;
> + spin_unlock(&nm_i->free_nid_list_lock);
> + kmem_cache_free(free_nid_slab, i);
> + nr_shrink--;
> + spin_lock(&nm_i->free_nid_list_lock);
> + }
> + spin_unlock(&nm_i->free_nid_list_lock);
> + mutex_unlock(&nm_i->build_lock);
> +
> + return nr - nr_shrink;
> +}
> +
> void recover_inline_xattr(struct inode *inode, struct page *page)
> {
> void *src_addr, *dst_addr;
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 509a2c4..4712dbc 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -317,6 +317,9 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
> if (!available_free_memory(sbi, NAT_ENTRIES))
> try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK);
>
> + if (!available_free_memory(sbi, FREE_NIDS))
> + try_to_free_nids(sbi, NAT_ENTRY_PER_BLOCK * FREE_NID_PAGES);
> +
> /* checkpoint is the only way to shrink partial cached entries */
> if (!available_free_memory(sbi, NAT_ENTRIES) ||
> excess_prefree_segs(sbi) ||
> diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
> index 9aa4235..da0d8e0 100644
> --- a/fs/f2fs/shrinker.c
> +++ b/fs/f2fs/shrinker.c
> @@ -23,6 +23,13 @@ static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
> return NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt;
> }
>
> +static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)
> +{
> + if (NM_I(sbi)->fcnt > NAT_ENTRY_PER_BLOCK)
> + return NM_I(sbi)->fcnt - NAT_ENTRY_PER_BLOCK;
> + return 0;
> +}
> +
> static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi)
> {
> return sbi->total_ext_tree + atomic_read(&sbi->total_ext_node);
> @@ -53,6 +60,9 @@ unsigned long f2fs_shrink_count(struct shrinker *shrink,
> /* shrink clean nat cache entries */
> count += __count_nat_entries(sbi);
>
> + /* count free nids cache entries */
> + count += __count_free_nids(sbi);
> +
> spin_lock(&f2fs_list_lock);
> p = p->next;
> mutex_unlock(&sbi->umount_mutex);
> @@ -97,6 +107,10 @@ unsigned long f2fs_shrink_scan(struct shrinker *shrink,
> if (freed < nr)
> freed += try_to_free_nats(sbi, nr - freed);
>
> + /* shrink free nids cache entries */
> + if (freed < nr)
> + freed += try_to_free_nids(sbi, nr - freed);
> +
> spin_lock(&f2fs_list_lock);
> p = p->next;
> list_move_tail(&sbi->s_list, &f2fs_list);
> --
> 2.4.2
>
>
>
> ------------------------------------------------------------------------------
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